Tactile warning surface, method, and apparatus

Abstract

A tactile warning surface has an array of tactile elements made of a composite material formed on the surface of an existing substrate. The preferred composite material is a mixture of a dry powder aggregate and a liquid SBR latex. The tactile elements are in the form of truncated cones or flattened domes having a height of about 0.20 inch and a diameter of about 1.0 inch. A method for installing the tactile warning surface includes the steps of placing a mold sheet having an array of mold apertures with shapes corresponding to the tactile elements over the substrate area, injecting the composite material in a semi-liquid state under pressure into the apertures of the mold sheet, allowing the injected composite material to cure and harden, then removing the mold sheet. For increased durability in traffic-bearing applications, a pigment/aggregate mixture can be applied as a coating over the tactile elements and substrate area. The tactile warning surface is installed using an injecting machine having a hopper for receiving the composite material and an access slot below for releasing it into the mold apertures of the mold sheet. The machine can also include a vibrator and arm extending into the hopper for vibrating the semi-liquid composite material.

Dependencies are inferred from the claim text.